Files
djhackersdev_minime/src/idz/common/setup.ts
T

82 lines
2.4 KiB
TypeScript

import { Socket } from "net";
import AesEcbStream from "./aes";
import { readBigInt, modPow, writeBigInt } from "./bigint";
import IoByteStream, { ByteStream } from "../../util/stream";
interface RsaKey {
N: bigint;
d: bigint;
e: bigint;
hashN: number;
}
export interface ClientHello {
pcbId: string;
protocol: string;
model: string;
}
export interface IdzConnection {
aesStream: ByteStream;
clientHello: ClientHello;
}
// Proof-of-concept, so we only ever use one of the ten RSA key pairs
const rsaKey = {
N: 4922323266120814292574970172377860734034664704992758249880018618131907367614177800329506877981986877921220485681998287752778495334541127048495486311792061n,
d: 1163847742215766215216916151663017691387519688859977157498780867776436010396072628219119707788340687440419444081289736279466637153082223960965411473296473n,
e: 3961365081960959178294197133768419551060435043430437330799371731939550352626564261219865471710058480523874787120718634318364066605378505537556570049131337n,
hashN: 2662304617,
};
// Proof-of-concept, so we only use one fixed session key
const aesKey = Buffer.from("ffddeeccbbaa99887766554433221100", "hex");
function writeServerHello(aesKey: Buffer, rsaKey: RsaKey): Buffer {
const M = readBigInt(aesKey);
const keyEnc = modPow(M, rsaKey.e, rsaKey.N);
const result = Buffer.alloc(0x48);
result.set(writeBigInt(keyEnc, 0x40), 0x00);
result.writeUInt32LE(0x01020304, 0x40); // Meaning is unknown
result.writeUInt32LE(rsaKey.hashN, 0x44);
return result;
}
function readClientHello(buf: Buffer) {
const magic = buf.readUInt32LE(0x00);
if (magic !== 0x01020304) {
throw new Error(
"Invalid magic number, cryptographic processing probably incorrect."
);
}
return {
pcbId: buf.slice(0x04, 0x0f).toString("ascii"),
protocol: buf.slice(0x10, 0x13).toString("ascii"),
model: buf.slice(0x18, 0x0c).toString("ascii"),
};
}
export default async function setup(socket: Socket): Promise<IdzConnection> {
const tcpStream = new IoByteStream(socket);
const serverHello = writeServerHello(aesKey, rsaKey);
await tcpStream.write(serverHello);
const aesStream = new AesEcbStream(tcpStream, aesKey);
const response = await aesStream.read(0x30);
if (response.length !== 0x30) {
throw new Error("Truncated client hello");
}
const clientHello = readClientHello(response);
return { aesStream, clientHello };
}